The possible use of stereoselective coordination to metal ion complexes for the separation and analysis of enantiomeric substances is outlined. This proposal discusses the development of asymmetric, substitution labile metal complexes containing additional coordination sites capable of interacting with the mixture to be separated. Because of the asymmetric nature of the complex, each diastereoisomer formed by coordination of an additional enantiomeric ligand has a different formation constant. The difference in formation constant of the mixed ligand complexes is utilized as the basis for the separation. Enantiomers are separated by using a solution of a suitable metal complex as the mobile phase in a liquid chromatograph. The roles of various structural features in determining the diastereoisomeric differences of the mixed ligand complexes are studied in order to provide a basis upon which suitable reagents can be designed. These structural features are studied without optical resolution of the diastereoisomers by contact shift nmr measurements of diastereo isomeric ratios in solution.